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arXiv · 1907.04173

Thermopower of the electron-doped manganese pnictide LaMnAsO

Manuel Zingl·Gernot J. Kraberger·Markus Aichhorn
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Abstract

Upon chemical substitution of oxygen with fluor, LaMnAsO has been electron-doped in experiments, resulting in samples with remarkably high Seebeck coefficients of around -300$\mu VK^{-1}$ at room temperature and 3% doping. Within the framework of density functional theory plus dynamical mean-field theory we are not only able to reproduce these experimental observations, but can also provide a thorough investigation of the underlying mechanisms. By considering electronic correlations in the half-filled Mn-3d shells, we trace the high Seebeck coefficient back to an asymmetry in the spectral function, which is due to emergence of incoherent spectral weight under doping and a strong renormalisation of the unoccupied states. This is only possible in correlated systems and cannot be explained by DFT-based band structure calculations.

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Manuel Zingl, Gernot J. Kraberger, Markus Aichhorn. 2019-07-09. Thermopower of the electron-doped manganese pnictide LaMnAsO. https://doi.org/10.1103/physrevmaterials.3.075404

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